The present invention relates to a device for holding lenses, especially eye glasses to be coated in a vacuum coating or sputtering machine, with a substrate holder consisting of cap-like sheet-metal blanks forming a dish in the form of a spherical segment, and with numerous drill-holes, that is mounted in the vacuum chamber above a coating source, revolving on a vertical axis, with the coating source mounted to the side of the axis of rotation, the lenses being placed in the drill holes and held and centered in the drill holes.
A device of the type in question is disclosed (U.S. Pat. No. 3,859,956) in which the lenses to be coated are inserted in rings which are in turn held by a frame located at a distance above the coating source. The rings can be tilted relative to the frame, in such a way that the lenses can be aligned with their curved surfaces towards the source. In this device the axis of rotation of the frame runs plumb through the source.
Another device is disclosed (DE-OS 39 21 672) for holding and turning lenses, specially for eye glasses to be coated in a high-vacuum coating machine or sputtering machine, with a pair of rings supporting the lens to be held. These, in turn, can be connected to a substrate holder that is held in the process chamber of the high-vacuum machine, with the cap-like or half-dish-shaped metal sheet forming the substrate holder at least partly overlapped by a sickle-shaped sheet-metal blank or sectional element forming a slide or rake. The edge of the rake facing towards the substrate holder is held a small distance away from the outer surface of the substrate holder by a slider or articulated arm, the rake being movable in this position relative to the top side of the substrate holder around the axis of rotation of the substrate holder.
A vacuum coating machine has also been proposed for depositing blooming coats on optical substrates (DE-OS 37 15 831) such as plastic eye lenses, that can be clamped on carriers rotating in an evacuatable container above evaporating sources. The carriers include a majority of flat carrier plates that are at least approximately in the shape of a segment of a circle, which are supported in a dome shape relative to each other and can each turn through 180.degree. at a common supporting axis of rotation. Each carrier plate has a majority of substrate mountings with at least one holding spring in the opening areas, of which at least one can tilt freely to both sides from the carrier plate plane up to a predetermined angle.
Finally a device has been disclosed (U.S. Pat. No. 4,449,478) for coating lens-shaped substrates including a cap-like substrate holder with several drill-holes arranged on two pitch circles to hold the lenses. The drill-holes are all aligned to the source located below the substrate holder, in such a way that the longitudinal axes of the drill-holes all intersect at the vertical axis of rotation of the substrate holder at one point. The coating source is located comparatively close to the point of intersection of the longitudinal axis.
An object of the present invention is to create a device of the type discussed above that enables largely even coating, even with machines in which the coating source is located not centrally beneath the substrate holder, but off center, near the axis of rotation of the cap-like substrate body. The device is also intended to be adjustable to the peculiarities of a coating source, for example the form of the "vaporization beam".